According to the prior art, hazard detectors have an interface by means of which the hazard detector is preferably connectable to a single fire detector and/or extinguishing control center. After the hazard detector responds or is triggered on the basis of an event, such as, for example, a fire, an event report is then sent from the hazard detector to a fire detector control center of a fire protection system. To this end, the hazard detectors are connected to the fire detector control center via a wire line.
The hazard detector allows one or more follow-up actions to be performed after the arrival of an event report at a fire detector control center about a detected event, for example a fire. An example of a follow-up action of this kind is automatic extinguishing, for example.
The electrical lines for transmitting a detected event are what are known as threshold value based circuits, for example, which can also be referred to as threshold value detector lines or current increase lines. The known threshold value based circuits result in events being reported by virtue of a prescribed constant voltage, for example 9 volts, being made available for the circuit by the fire detector and/or extinguishing control center, for example. The circuit comprises a two-wire line, for example, the two lines having a constant voltage applied to them at one end by the fire detector and/or extinguishing control center. At the other end of the two-wire lines, the two lines are connected to one another by means of a terminating resistor. On account of the terminating resistor, a predefined, substantially constant current flows through the circuit.
The hazard detectors are now connected in parallel with the terminating resistor, for example, each hazard detector having a current sink, for example a switchable internal resistance, and, in an event situation, connecting this internal resistance to the circuit such that the total current measured by the fire detector and/or extinguishing control center at the input of the circuit increases.
By detecting this current increase in the fire detector and/or extinguishing control center, it is now possible to infer an event, which means that said event can be reacted to by the fire detector and/or extinguishing control center in a suitable manner.
As a result of the advancing automation in buildings, however, there is ever more frequently the desire to connect a hazard detector that is present anyway to not just one evaluation unit, such as a fire detector and/or extinguishing control center, in order to use the sensor data. Rather, it is thus desirable to also electrically connect the hazard detector to further evaluation units besides the fire detector and/or extinguishing control center. Examples of such further evaluation units are further fire detector control centers of a third-party supplier different than the hazard detector manufacturer, building management systems or even further units, such as further modules of the same fire detector and/or extinguishing control center, for example in order to use different connections of the hazard detector to the same fire detector and/or extinguishing control center to interchange different signals between the hazard detector and the fire detector and/or extinguishing control center.
In this case, however, the problem arises that, if, by way of example, an evaluation unit retrieves data from a hazard detector for which signals are transmitted to the hazard detector or from the hazard detector to the evaluation unit in the form of voltage or current variations, a further evaluation unit connected to the hazard detector could already interpret the variations as an event and then trigger an alarm. Even if, by way of example, different interfaces were provided for two different evaluation units, the actuating of the hazard detector via the one interface would mean that current flows are produced in the hazard detector that could be the result of a potential equalization between the interfaces, for example. In this case too, there would then be the risk that such currents would also be measurable at the further interface, which means that they would be detected as an event by the further evaluation unit and could therefore result in false alarms.
Against this background, the invention was based on the object of specifying a hazard detector that overcomes the disadvantages found in the prior art to the greatest possible extent. It is thus an object of the present invention to find a hazard detector and a method for transmitting a hazard signal that allows multiple evaluation units to be electrically connected to a single hazard detector.
To achieve this object, the invention comprises a hazard detector for an evaluation unit. The evaluation unit is a fire detector and/or extinguishing control center, for example. The hazard detector is a combustion gas or fume detector, a heat detector, a smoke detector, a spark detector or a flame detector, for example. The hazard detector is also a detector for thermal decomposition processes, for example.
The hazard detector comprises a housing and at least one sensor unit or a sensor interface for connecting the sensor unit. The sensor unit is used for capturing a hazard parameter, which is a fire parameter, for example. A fire parameter is an increased ambient temperature or an increased amount of smoke particles, for example.
The sensor unit or the sensor interface further has a first electronic assembly electrically connected to it. The first electronic assembly is used for processing sensor signals of the sensor unit. These sensor signals are accordingly representative of a hazard parameter, for example. The electrical connection to the sensor unit or the sensor interface is accordingly used to transmit the hazard parameter captured using the sensor unit to the first electronic assembly as a sensor signal.
Moreover, the invention comprises a second electronic assembly and a first interface. The first interface and the second electronic assembly are electrically connected to one another. The first interface is used for electrical connection to a physically remote evaluation unit. Accordingly, the connection of the second electronic assembly to the first interface is therefore used for indirectly connecting the physically remote evaluation unit to the second electronic assembly.
Further, the first electronic assembly and the second electronic assembly have a wireless data connection for transmitting the processed sensor signals from at least the first electronic assembly to the second electronic assembly. At least the first electronic assembly and the second electronic assembly are arranged inside the housing.
According to the invention, a hazard variable is accordingly detected using a sensor unit of the hazard detector or using a sensor unit connected to a sensor interface of the hazard detector. The sensor signals of the sensor unit are then processed using a first electronic assembly of the hazard detector, which electronic assembly is electrically connected to the sensor unit. A processing comprises an analog-to-digital conversion and/or a boosting of the signals, for example. The processed sensor signals are then transmitted from the first electronic assembly to a second electronic assembly of the hazard detector inside the housing of the hazard detector using a wireless data connection. The second electronic assembly transmits the processed sensor signals, which have previously been transmitted wirelessly, by means of a first interface, which is electrically connected to the second electronic assembly, to a physically remote evaluation unit. The evaluation unit, which is a fire detector control center, for example, can then initiate follow-up measures in a fire situation.
The wireless data connection allows signals to be output on the first interface for electrical connection to a physically remote evaluation unit independently of the potentials representing the sensor signals or the processed sensor signals.
According to a first advantageous embodiment, the first electronic assembly and the second electronic assembly are DC isolated from one another. That is to say that the two assemblies have no electrically conductive connection at all.
According to a further embodiment, the first electronic assembly is configured to receive sensor signals obtained from the sensor unit or the sensor interface, which can also be referred to as hazard signals. The first electronic assembly is then configured to interpret these sensor signals or hazard signals for the existence of an alarm situation. Further, the first electronic assembly is configured so as, if an alarm situation exists, to generate an alarm signal representative of the alarm situation.
Overall, the hazard detector is thus configured to transmit the alarm signal via the wireless data connection to the second electronic assembly and from the second electronic assembly via the first interface to an evaluation unit. Accordingly, the hazard signal is thus first of all interpreted for the existence of an alarm situation using the first electronic assembly. Accordingly, the first electronic assembly has already provided an indicator allowing the existence of an alarm situation to be recalled or detected by means of an alarm signal. As provided for according to this exemplary embodiment, this alarm signal can be transmitted to the second electronic assembly and hence to the first interface via the wireless connection.
The transmitting of a representative alarm signal instead of the sensor signal per se allows a robust wireless data transmission, since only a small volume of data is necessary in order to transmit either the existence of an alarm situation or the existence of no alarm situation in the form of the alarm signal. By contrast, if the sensor signals, in particular the raw sensor signals, were transmitted via the wireless data connection without the preprocessing using the first electronic assembly, then high data transmission rates would be necessary. These high data transmission rates would not be compatible with the requirements of high interference immunity, as are desired and frequently stipulated for security devices.
According to a further embodiment, the evaluation unit is a physically remote fire detector and/or extinguishing control center, a programmable logic controller, a building management system or an actuator of an extinguishing installation. Such an actuator is a solenoid valve, for example.
According to a further embodiment, the wireless data connection comprises a first and a second transceiver. In this arrangement, the first electronic assembly comprises the first transceiver and the second electronic assembly comprises the second transceiver. By way of example, the first and second transceivers are each optical transceivers, such as, for example, IrDA transceivers. Alternatively, the first and second transceivers are radio transceivers, such as, for example, Bluetooth or NFC transceivers.
An advantage of a wireless data connection in the form of transceivers is a bidirectional communication between the first and second electronic assemblies. Accordingly, the wireless data connection can be used not only to transmit alarm signals from the first electronic assembly to the second electronic assembly, but status query signals, for example, can also be transmitted in the opposite direction from the second electronic assembly to the first electronic assembly.
The use of IrDA transceivers, Bluetooth or NFC transceivers is advantageous because they are standardized in large numbers and are thus available particularly cheaply. This allows cheap production of the hazard detector per se.
According to a further embodiment, the wireless data connection is configured to interchange data with a third transceiver arranged outside the housing. By way of example, it is thus possible to bring an external device having this third transceiver into the area of the housing and to interchange data with the first electronic assembly and/or the second electronic assembly. An advantage in this case is that the wireless data connection that already exists can be used to perform service operations at the hazard detector, such as, for example, calibration or installation following startup, in a simple manner using an external device.
In this case, it is naturally possible for the third transceiver likewise to be an optical transceiver or a radio transceiver. In the case of an optical transceiver, the housing of the hazard detector has an optically transmissive area for optical connection of the third transceiver to the first and second transceivers.
According to a further advantageous embodiment, the first electronic assembly is connected to a second interface directly or indirectly. The second interface is configured to supply the first electronic assembly and additionally or alternatively the sensor unit with power for operation.
According to this embodiment, the second interface is additionally or alternatively configured to set up a data connection to the evaluation unit or a further evaluation unit.
Accordingly, a second interface connected to the first electronic assembly is thus provided according to this embodiment. This interface is accordingly used merely for supplying power, or alternatively for data connection to the evaluation unit or a further evaluation unit or for supplying power and for data connection. The first and second interfaces are accordingly connected to one another by the wireless data connection of the first and second electronic assemblies, the supply of electricity and/or a data interchange with the electronic assemblies each being effected via a separate interface. Electrical signal alterations on either the first or the second interface accordingly cannot result in signal alterations on the other of the two interfaces on account of unwanted potential equalization currents.
According to a further advantageous embodiment, the housing has a housing upper part and a housing lower part. The housing upper part and the housing lower part are detachably connectable to one another. At least the first electronic assembly is mechanically connectable or connected to the housing upper part and at least the second electronic assembly is mechanically connectable or connected to the housing lower part.
This connection holds the two assemblies securely in the housing, the first electronic assembly being mechanically connected only to the housing upper part and the second electronic assembly being mechanically connected only to the housing lower part. This allows the housing to be easily opened.
Electrical connections between the first and second electronic assemblies have accordingly been dispensed with, which means that it is not necessary for any electrical connections between the first and second housing upper parts to be broken when the housing is opened. The separate replacement of the housing upper part or the housing lower part for a hazard detector in the event of a fault, for example in the upper part or in the lower part, is therefore easily possible.
According to a further embodiment, the housing lower part comprises the second interface, the second interface being in the form of a power supply and signal distribution apparatus, preferably in the form of a terminal strip. The second electronic assembly is in the form of a relay module and/or an interface module. Additionally or alternatively, the second electronic assembly is a relay module, a communication module and/or an interface module having the first interface.
Moreover, the invention relates to a system having at least one hazard detector according to one of the aforementioned embodiments and having an evaluation unit, which is a remote fire detector and/or extinguishing control center, a programmable logic controller, a building management system or an actuator of an extinguishing installation.